Various types of medical devices employ a needle for piercing the skin of a patient for diagnostic or therapeutic purposes. One such device is a device for introducing medicine from a pre-filled cartridge into a patient. Handling of such medical devices after the needle is withdrawn from the patient can result in transmission of various pathogens, most notably human immunodeficiency virus (HIV), due to an inadvertent needle stick to medical personnel.
Several devices are known that allow fluid to be injected into a patient from a pre-filled cartridge. For instance, in dental practice, a cartridge injector is used for injecting novocaine into a patient. These cartridge injectors are normally made with metal, that may be chrome or nickel plated and are intended to be sterilized by an autoclave after use.
When using a dental injector, it is common to administer several small doses of novocaine. After the first injection, the needle is considered contaminated, and current practice, as outlined by OSHA guidelines, requires recapping the needle. Although recapping by hand is prohibited by OSHA guidelines, some dentists still practice this unsafe technique, which can lead to an inadvertent needle stick. One recommended technique for safely recapping the needle uses a cap holder, mounted to the dental tray being used. Although safer than recapping the needle by hand, using a cap holder still exposes the contaminated needle when the device is moved from the patient's mouth to the cap holder for recapping. Another problem with recapping is that if the dentist is not careful when centering the needle into the cap, the needle tip can scrape the sidewall of the cap. If this happens, the needle can be dulled or can scrape off small pieces of plastic that could be injected into the patient during subsequent injections.